Troops pounded parts of a northern Nigeria city overnight after reinforcements were sent in to help rout fleeing members of an extremist sect whose base they razed, witnesses said.

Residents and an AFP reporter heard sounds of heavy and light machine gun fire rattling across sections of the capital not previously targetted on the fifth day of deadly clashes.

The latest gunbattles came just hours after the army announced bolstering its ranks with 1000 more soldiers to fight members of the self-styled Taliban sect.

"Fighting is still going on between the military and Boko Haram. Throughout the night, we heard gunfire coming from Shokai and Dekwa Lowcost (suburbs)," Mala Bukar, a resident of an adjacent neighbourhood told AFP.

"Up to this morning fighting is still continuing and from where we are we can hear the sound of heavy and light machineguns," he added.

An army commander said members of the Nigerian Islamist fundamentalist sect fled their bases in northern city of Maiduguri on Wednesday after the military overran their mosque and leader's house base.

Colonel Ben Ahonotu, commander of the operation against the self-styled Taliban told AFP: "We have taken over their enclave, they are on the run and we are going after them."

Residents said they saw scores of militants pass through their area Wednesday heading out of the city, some of them disguising themselves by cutting off their hair and beards.

Boko Haram members flee

"We spotted dozens of members of Boko Haram fleeing. They stopped by briefly, shaved their hair and beard and discarded their trademark jellabiyah (white arabic caftans) for tee-shirts and jeans, and moved on," said Hamad Bulunkutu told AFP.

"They crossed the Gamboru market river and disappeared from there," he added.

Maiduguri, capital of Borno state, has seen the worst of the unrest in northern Nigeria which started on Sunday in Bauchi state when militants attacked a police station.

It has been the birthplace and stronghold of the fundamentalists who are opposed to Western education and values.

The Nigerian extremists emerged in 2002 in Maiduguri before setting up a camp on the border with Niger, from where they launched a series of attacks on the police.

The leadership has previously said it intends to lead an armed insurrection and rid society of "immorality" and "infidelity".

President Umaru Yar'Adua had ordered the armed forces to crush the movement "once and for all".

Fighting on Wednesday concentrated on enclaves of Maiduguri believed to house the sect's leader Mohammed Yusuf. The death toll from the clashes has already surged past 300 and thousands of people have been forced to flee their homes to escape the violence.